Green is good! At least, that’s what we’re taught in our science classes when it comes to plants. Plants with healthy green leaves are busy getting down, doing photosynthesis (which, being a biochemical process, is actually the antithesis of getting down). They’re growing and becoming the mature leafy plant life that eventually animals like cows—or, you know, us—will eat for sustenance.

So why would a plant develop a pattern on its leaves that’s white? Why would a plant include code in its genes for a part of the leaf that doesn’t perform photosynthesis as well?

The photo that inspired this post.

White clover, known scientifically as Trifolium repens, exists throughout Europe, North America, and parts of the Pacific. A lot of people reading this blog have seen it, I bet. Chances are that a few of us as kids plucked it and shouted something like, “I found a lucky clover!” while holding a bunch of it in a small bouquet. Presenting our white clovers in a cluster, we reasoned, made it that much harder to tell that the plants we found growing everywhere really had three leaves instead of the fabled four. How clever we were! (Or, how clever I was, if I’m the only dork here who was sure that that would work.)

Okay, so we/I sucked at getting the adults around us to see what we wanted them to see. Trifolium repens, however, is actually very good at getting the creatures that eat it to notice exactly what’s important.

One widespread form of white clover (which has white flowers, if you were wondering) has leaves that are solidly green, just as you‘d expect from a plant. In contrast, another variety has a pale v-shaped stripe in the center of each leaflet.

That stripe doesn’t exist just for pretties. The variety of white clover with the v-stripe, sometimes known unsurprisingly as “white-striped clover,” produces cyanide inside its cells. It makes just enough of that lethal compound to cause problems for small creatures like snails and slugs that otherwise would eat whatever clover they could find in low-lying areas.

It should come as no shock that the striped white clover is the more common form of clover along low-altitude coastlines like that of Long Island, New York, of the shores of North Carolina, where plant-eating molluscs like to slither. Survival of the fittest, baby! The molluscs in such places have learned that that stripe means danger and so the striped clover lives on. If you want to see the plain form of white clover in abundance, Minnesota is cool. Not as many shell-toting animals in those plains thereas there are by the ocean.

Even if striped white clover is toxic to small animals (and even if any kind of white clover’s ability to grow quickly across a large area of land has led most people label it a weed), it is a green plant, and green is still good: